Information communication system, content catalog information distributing method, node device, and the like

Abstract

A node device includes: destination information storing means for storing destination information of representative node devices belonging to the groups; content catalog information receiving means for receiving content catalog information transmitted from another node device, the content catalog information being one in which attribute information of content data which can be obtained by the information communication system is written; content catalog information transmitting means, in the case where the group to which the node device itself belongs is further divided in a plurality of groups in accordance with the predetermined rule, for transmitting the received content catalog information to the representative node devices belonging to the groups in accordance with destination information of the representative node devices belonging to the groups further divided; and content catalog information storing means for storing all or part of the received content catalog information.

1 . A node device included in an information communication system having a plurality of node devices capable of performing communication with each other via a network, the plurality of node devices being divided in a plurality of groups according to a predetermined rule,
 the node device comprising:   destination information storing means for storing destination information of representative node devices belonging to the groups;   content catalog information receiving means for receiving content catalog information transmitted from another node device, the content catalog information in which attribute information of content data which can be obtained by the information communication system is written;   content catalog information transmitting means, in the case where the group to which the node device itself belongs is further divided in a plurality of groups in accordance with the predetermined rule, for transmitting the received content catalog information to the representative node devices belonging to the groups in accordance with destination information of the representative node devices belonging to the groups further divided; and   content catalog information storing means for storing all or part of the received content catalog information.   
   
   
       2 . The node device according to  claim 1 ,
 wherein each time content catalog information stored in another node device is updated, attribute information of content data of an updated portion in the content catalog information is written in the content catalog information, the resultant information is transmitted as updated-portion content catalog information,   the content catalog information receiving means receives the updated-portion content catalog information transmitted from another node device,   in the case where the group to which the node device itself belongs is further divided in a plurality of groups in accordance with the predetermined rule, the content catalog information transmitting means transmits the received updated-portion content catalog information to representative node devices belonging to the groups in accordance with destination information of the representative node devices belonging to the further divided groups, and   the content catalog information storing means stores the received updated-portion content catalog information.   
   
   
       3 . The node device according to  claim 2 ,
 wherein version information indicative of a version is added to the updated-portion content catalog information, and   the node device further comprises:   version comparing means for comparing the version information added to the received updated-portion content catalog information with version information added to the content catalog information already stored; and   updating means, in the case where, as a result of comparison of the version comparing means, the version information added to the received updated-portion content catalog information is newer than the version information added to the already stored content catalog information by one, for updating the already stored content catalog information and its version information on the basis of the attribute information of the content data written in the received updated-portion content catalog information and its version information.   
   
   
       4 . The node device according to  claim 2 ,
 wherein version information indicative of a version is added to the updated-portion content catalog information, and   the node device further comprises:   version comparing means for comparing the version information added to the received updated-portion content catalog information with version information added to the content catalog information already stored; and   updating means, in the case where, as a result of comparison of the version comparing means, the version information added to the received updated-portion content catalog information is newer than the version information added to the already stored content catalog information by two versions or more, for obtaining updated-portion content catalog information corresponding to version information to be positioned between both of the version information from the another node device, and for updating the already stored content catalog information and its version information on the basis of the obtained updated-portion content catalog information, the received updated-portion content catalog information and its version information.   
   
   
       5 . The node device according to  claim 2 ,
 wherein version information indicative of a version is added to the updated-portion content catalog information, and   the node device further comprises:   version comparing means for comparing the version information added to the received updated-portion content catalog information with version information added to the content catalog information already stored,   wherein in the case where the version information added to the received updated-portion content catalog information is older than the version information added to the already stored content catalog information as a result of comparison of the version comparing means, the content catalog information transmitting means adds version information indicative of the new version to updated-portion content catalog information corresponding to a version newer than the version of the received updated-portion content catalog information, and transmits the resultant information to the another node device.   
   
   
       6 . The node device according to  claim 1 , further comprising:
 range information storing means for storing service range information indicative of a service range of the node device in content data which can be obtained in the information communication system and corresponds to the group to which the node device belongs; and   content specifying means for specifying content data in the service range indicated by the service range information, in the content data whose attribute information is written in the received content catalog information,   wherein the content catalog information storing means stores at least the content catalog information in which the attribute information of the specified content data is written.   
   
   
       7 . The node device according to  claim 6 ,
 wherein content identification information as unique identification information made of a predetermined number of digits is associated with each of the content data which can be obtained in the information communication system,   node identification information as unique identification information made of the predetermined number of digits is associated with each of the node devices provided for the information communication system,   the service range information indicates the number of digits to be matched with node identification information of the node itself and the content identification information, as the number of digits which decreases as the service range is widened, and   the content specifying means specifies content data corresponding to the content identification information in which a predetermined digit of a predetermined number of digits to be matched which is indicated by the service range information matches the node identification information of the node itself, in content data whose attribute information is written in the received content catalog information.   
   
   
       8 . The node device according to  claim 6 ,
 wherein a service range indicated by the service range information is set to be narrower as storage capacity of the content catalog information storing means is smaller.   
   
   
       9 . The node device according to  claim 6 , further comprising:
 service range changing means, when content catalog information in which attribute information of the specified content data is written is stored and then a data amount of content catalog information stored in the content catalog information storing means becomes equal to or larger than a predetermined amount, for changing a service range indicated by the service range information stored in the range information storing means so as to be narrowed; and   catalog information deleting means for deleting, from the content catalog information, attribute information of content data which lies out of the changed service range, in the content data whose attribute information is written in the content catalog information stored in the content catalog information storing means.   
   
   
       10 . The node device according to  claim 6 ,
 wherein each time content catalog information stored in another node device is updated, attribute information of content data of an updated portion in the content catalog information is written in the content catalog information, the resultant information is transmitted as updated-portion content catalog information,   the content catalog information receiving means receives the updated-portion content catalog information transmitted from another node device,   in the case where the group to which the node device itself belongs is further divided in a plurality of groups in accordance with the predetermined rule, the content catalog information transmitting means transmits the received updated-portion content catalog information to representative node devices belonging to the groups in accordance with destination information of the representative node devices belonging to the further divided groups,   the content specifying means specifies content data in a service range indicated by the service range information, in content data whose attribute information is written in the received updated-portion content catalog information, and   the content catalog information storing means stores at least content catalog information in which attribute information of the specified content data is written.   
   
   
       11 . The node device according to  claim 10 ,
 wherein version information indicative of a version is added to the updated-portion content catalog information, and   the content catalog information storing means stores version information added to the updated-portion content catalog information also in the case where even one piece of content data is not specified from content data whose attribute information is written in the received updated-portion content catalog information.   
   
   
       12 . A recording medium in which a node process program for making a computer function as a node device of  claim 1  is computer-readably recorded. 
   
   
       13 . An information communication system having a plurality of node devices capable of performing communication with each other via a network, the plurality of node devices being divided in a plurality of groups according to a predetermined rule,
 wherein the node device comprises:   destination information storing means for storing destination information of representative node devices belonging to the groups;   content catalog information receiving means for receiving content catalog information transmitted from another node device, the content catalog information being one in which attribute information of one or plural pieces of content data which can be obtained by the information communication system is written;   content catalog information transmitting means, in the case where the group to which the node device itself belongs is further divided in a plurality of groups in accordance with the predetermined rule, for transmitting the received content catalog information to the representative node devices belonging to the groups in accordance with destination information of the representative node devices belonging to the groups divided; and   content catalog information storing means for storing all or part of the received content catalog information.   
   
   
       14 . A content catalog information distributing method in an information communication system having a plurality of node devices capable of performing communication with each other via a network, the plurality of node devices being divided in a plurality of groups according to a predetermined rule, comprising:
 a process of receiving content catalog information transmitted from another node device by a node device, the content catalog information being one in which attribute information of content data which can be obtained by the information communication system is written;   a process, in the case where the group to which the node device itself belongs is further divided in a plurality of groups in accordance with the predetermined rule, of transmitting the received content catalog information by the node device to the representative node devices belonging to the groups in accordance with destination information of the representative node devices belonging to the groups divided; and   a process of storing all or part of the received content catalog information by the node device.